Food Heat and Cold Engineering

Total Hours in Course162

Number of hours for lectures32

Number of hours for laboratory classes32

Independent study hours98

Date of course confirmation13.04.2021

Responsible UnitInstitute of Food

Course developers

prof.

Ruta Galoburda

Dr. sc. ing.

Pārtikas institūts

Elīna Sturmoviča

Dr. sc. ing.

Prior knowledge

Fizi2016, Physics

MašZ4023, Engineering Graphics

Mate4019, Mathematics I

Mate4020, Mathematics II

Meha4013, Theoretical Mechanics

PārZP029, Introduction in Food Industry

Course abstract

Obligatory course for students of the second-level professional higher education study program "Food product technology"

Learning outcomes and their assessment

After completing the course student will have:
• knowledge on basic principles of heat and cold production, and their use in food industry – lectures, four theory tests;
• skills to perform calculations of heat equipment and cold rooms, selecting appropriate refrigeration units, to explain role of different units in work of refrigeration equipment - three calculus test, independent work on refrigeration/freezer room calculation;

• competences to argument selection of operational parameters of heat and refrigeration equipment, to explain safety and exploitation requirements - laboratory works, theoretical studies on the selected topics.

Course Content(Calendar)

Application of refrigeration in food industry. (Lectures – 2 h)
2. Methods for obtaining low temperatures. Refrigerants, their physical, thermodynamic, and physiological characteristics. Refrigerant pressure-enthalpy charts. (Lectures – 2 h, Laboratory work – 2 h)
3. Freezer and cooler rooms. Presentations of theoretical study on refrigeration processes. (Lectures – 2 h, Laboratory work – 4 h)
4. Operating principles of mechanical refrigeration, refrigeration cycle in pressure-enthalpy charts. Calculation of refrigeration cycle. 1st theory test on topics 1–4. 1st test on refrigeration cycle calculations. (Lectures – 3 h, Laboratory work – 8 h).
5. Scheme of absorption cooling system, operating principle, heat balance, cooling efficiency coefficient. Scheme of thermoelectric cooler (Peltier element) and its operating principle. (Lectures – 2 h)
6. Compressors of the mechanical refrigeration unit. Heat exchangers in the refrigeration unit. (Lectures – 2 h)
7. Direct and indirect cooling systems. Air cooling systems. (Lectures – 1 h)
8. Refrigeration components, devices, and mechanisms. Basic principles of refrigeration unit control and operation. 2nd theory test on topics 5–8. (Lectures – 2 h, Laboratory work – 2 h).
9. Types and characteristics of heat carriers. Their application to the food industry. Parameters for working substances. Normal conditions of the working substance. Perfect gas, gas blends. (Lectures – 2 h)
10. Gas developments (isochoric, isobaric, isothermal, adiabatic, polytrophic). Cycles, their meaning and use. 3rd theory test on topics 9–10. 2nd test on heat calculations in gas cycles. (Lectures – 2 h, Laboratory work – 2 h).
11. Water vapour, its use. Types of steam. Heat consumption for steam extraction. Determination of water vapour parameters and energy levels using charts and tables. (Lectures – 3 h, Laboratory work – 8 h).
12. Air as heat transfer. Description of the air. Types of air humidity expression. Determining air parameters using a chart. Use of air as a heat transfer. 4th theory test on topics 11–12. 3rd test on calculation of steam and air, using charts and tables. (Lectures – 2 h, Laboratory work – 4 h)
13. Heat displacement and ways of transferring it. Heat management, its calculation. Heat insulation materials, their characteristics. Radiation, its calculation. Convection, its expression, its characteristic. Complex heat movement, its characteristics. (Lectures – 2 h)
14. Heat exchange. The concept of heating surface, its calculation. Heat return and heat transition processes, their characteristics. Thermal resistance, determination thereof. Temperature difference, determination. Heat exchange manifestations and technical equipment. (Lectures – 2 h, Laboratory work – 2 h)
15. Heat extraction. Main sources of heat extraction. Fuel types. Fuel components, combustible, ballasting parts. Heat of combustion, determination thereof. Notional fuel, fuel equivalent. Fuel burning, complete, incomplete. (Lectures – 1 h)

16. Steam and hot water production plants. Boiler types, characteristics. Basic components of boiler structure. Characteristics and purification of boiler-feeding water. Boiler heat balance. Presentations of theoretical study on thermotechnics. (Lectures – 2 h).

Requirements for awarding credit points

Completed all laboratory works.
Successfully completed all tests (score at least 4).
Written and publicly defended theoretical study on the use of refrigeration in the food industry. A calculation of refrigeration/freezer facilities for the storage of a specific product has been performed.

Description of the organization and tasks of students’ independent work

Theoretical studies in preparation for tests.
Collection and analysis of information in preparation for laboratory work, independent work on refrigeration/freezing room calculation, and development of theoretical research on the selected topics.

Criteria for Evaluating Learning Outcomes

All tests should be successfully completed (score at least 4). The grade of the cumulative exam is calculated as average from all grades.

Compulsory reading

1. Nagla J. Siltumenerģētikas teorētiskie pamati. J.Nagla, P.Saveļjevs, D.Turlajs. Rīgas Tehniskā universitāte. Transporta un mašīnzinību fakultāte. Siltumenerģētisko sistēmu katedra. Rīga: Rīgas Tehniskā universitāte, 2008. 192 lpp.
2. Šeļegovskis R. Siltuma ieguves tehnoloģijas: metodiskais materiāls studiju priekšmeta "Siltumapgādes avoti" teorētiskās daļas apguvei. Jelgava: LLU, 2008.
3. Холодильная техника и технология: учебник для студентов вузов. Москва : ИНФРА-М, 2000. 285 c.
4. Fellows P.J. Food Processing Technology. Cambridge, England: Woodhead Publishing Ltd., 2000. 575 lpp.

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